The subject disclosure is directed generally to raster printing enhanced black, and more particularly to selectively printing enhanced black.
Raster printing systems accomplish printing by forming small marks or dots at selected pixel locations, and are commonly implemented as electrophotographic printers and ink jet printers. In raster printing systems, it is known to print one or more non-black color dots (e.g., cyan, magenta or yellow) with black dots, for example to improve black density and uniformity in dark gray regions. However, since color-to-color registration can be less than ideal, it may be preferable not to add non-black color to black near edges where color fringes will tend to show if mis-registration is present. This can be particularly important in light half-toned grays where even a slight mis-registration could induce a noticeable hue shift.
While there are known techniques directed to reducing color fringes, they can be complex and computationally expensive.